Derivative Income (Loss) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative loss
Warrant liability fair market adjustment	$ 1,688	$ (1,344)
Derivative income (loss)	(778)	553
Warrant Liability
Derivative loss
Warrant liability fair market adjustment	1,700	(1,300)
Level 3 | Sentient Loan
Derivative loss
Derivative income (loss)	$ 800	$ (600)
Level 3 | Warrant Liability | Sentient Loan
Fair value Assumptions
Stock price (in dollars per share)	$ 0.58	$ 0.20
Volatility (as a percent)	110.00%	85.00%
Risk free interest rate (as a percent)	1.39%	1.48%